Re-add imported and fix value for named imports

[Ayc0]

In the readme, we mention that we expose:

export const importStatements = [
    {
        module: "@blocz/elements",
        imports: [
            {
                kind: "named",
                imported: "Button",
                local: "Button",
                value: this_is_the_value_of_the_variable_Button
            },
            {
                kind: "named",
                imported: "Tabs",
                local: "Tabulations",
                value: this_is_the_value_of_the_variable_Tabs
            }
        ]
    }
];

But we forgot to include the imported value.

Also the value was bound to the imported field, and when an import is renamed, like import { foo as bar }, then the variable foo is not defined anymore in the MDX, resulting in a crash when loading the MDX: Uncaught ReferenceError: foo is not defined.